In recent years, a touch panel has been laminated on a screen of a mobile phone, banking terminal, game machine or the like in some cases. A user manipulates such an apparatus by touching a specific portion on the touch panel with his/her finger, a pen or the like while visually identifying a button or an icon displayed on the screen of the apparatus.
Further, in recent years, there are developed techniques for presenting a tactile sense to a user when the user touches a screen of an apparatus. As the techniques, there are a technique disclosed in Patent Literature 1, and a technique disclosed in Patent Literature 2.
Patent Literature 1 discloses a tactile sense presentation device including a touch panel having a plurality of planar electrodes is disposed for presenting a tactile sense on a rear surface thereof. In this device, a voltage which changes temporally is applied to the planar electrode. When a finger approaches the electrode to which the voltage is applied, an electrode-finger-electrode circuit is formed. Herein, an electric field is generated between the finger and the electrode, and an electrostatic force based on the electric field forms a tactile sense to be presented to the finger.
Patent Literature 2 discloses a touch panel device with a tactile sense presenting function, the touch panel device including piezoelectric elements. According to this disclosed technique, the touch panel device with the tactile sense presenting function realizes a function as a touch panel and a function as a tactile sense presentation device, with one panel having the piezoelectric elements.